Field of the Invention
The present invention relates to an image display device, and more particularly, to a stereoscopic image display device.
Discussion of the Related Art
Stereoscopic image display devices may be divided into stereoscopic image display devices of a glasses mode and a glassless mode, depending on the need for glasses.
Among the stereoscopic image display devices, glassless-mode stereoscopic image display devices generally realize three-dimensional (3D) images when an optical element capable of causing parallax between left-eye and right-eye images is installed in front of a display screen. The optical element having such a function includes a lenticular lens, a parallax barrier, etc.
The parallax barrier realizes a stereoscopic image by arranging vertical slits for transmitting or shielding light at constant distances and separating right and left images through the vertical slits, and the lenticular lens realizes stereoscopic images by attaching a lens in a curved lenticular array shape to a display panel and allowing a left eye and a right eye to see different pixels to separate right and left images.
However, in related art stereoscopic image display devices, an optimal viewing distance is generally determined by pitches of unit lenses in a parallax unit or pitches of certain periods of unit slits. In this case, it is impossible to ensure an optimal viewing distance greater than or equal to a predetermined distance due to limitations on resolution which may be realized with pitches.
Therefore, an alternative plan to provide a separate gap glass in the front or rear of the parallax unit to extend an optimal viewing distance has been proposed, but has a problem in that the thickness of the stereoscopic image display device increases, which makes it possible to manufacture a slim stereoscopic image display device.